class A {
  a1: string = ''
  a2: string = ''
  a3: string = ''
}

class B {
  b1: number = 0
  b2: number = 0
  b3: number = 0
}

// 要求一个接口要有 A 和 B 的所有成员

interface C extends A, B {}

const d:C = {
  a1: "",
  a2: "",
  a3: "",
  b1: 0,
  b2: 0,
  b3: 0
}